Material feeding apparatus



1945, w. R. SCHMITZ. JR 2,383,085

MATERIAL FEEDING APPARATUS Fi ed April 29, 1943 4 SheetS- -Sheet 1 10/55 DRIVE fig, I

William Elk/2am Jmgm mm 21, .1945 w. R. SCHMITZ, JR 2,

MATERIAL FEEDING APPARATUS Filed April 29, 1943 4 Sheets-Sheei; 2

Hanan Aug. 21., 1945. w sc n-z, JR 2,383,085-

' MATERIAL FEEDING APPARATUS Filed April 29, 1943 4 Sheets-Sheet 3 mamMm JM@,./K MW XWz/4 Aug. 21, 1945. w. R.'$CHM|TZ, JR 2,333,035

MATERIAL FEEDING APPARATUS Filed April 29, 1943 4 Sheets-Sheet 4 From41'!" Valve 1 64a i Q 4 2m I l 66 4 54 F/'z i5 g/63 William Ric/54rdfilmguh .INVENTOR.

Patented Aug. 21, 1945 MATERIAL FEEDING APPARATUS William RichardSchmitz, In, Wilmington, Del.,

assignor to E. I. du Pont de Nemours & Company, Wilmington, Del., acorporation of Delaware Application April 29, 1943, Serial No. 484,957

6 Claims.

This invention relates to apparatus for controlled feeding of materialsto a receiving means. More particularly, it relates to apparatus forfeeding sheets of cellulose at a constant rate to a reaction vessel,which apparatus is especially adapted for use in the continuousproduction of alkali cellulose.

For the successful operation of a continuous process, it is necessary,among other things, to feed the raw materials at a constant and uniformrate into the reaction chamber or other receiving apparatus employed. Ofthe several methods proposed to accomplish this uniform feed, the "lossof weight principle has generally proven the most successful. Accordingto this principle, an amount of raw material sufficient for an extendedperiod of operation is placed on a feeding means supported on a scalemechanism, the scale being brought by hand to a position of balance atthe terial into this means at a speed somewhat greater than that calledfor by the movement of the poise. Thus, after a short period ofoperation, the scale is again in a condition of balance and the actionof the feeding mechanism is stopped. The continuing, uniform advance ofthe poise, however, soon creates a new condition of unbalance that againplaces the feeding mechanism in operation. Although the raw material isfed into the reaction chamber or receiving means in an intermittentrather than continuous fashion, the intervals during which the feedingmechanism is at rest are so short that the feeding is substantiallycontinuous in nature.

raw material is delivered by the mechanism. No means has yet beenprovided to compensate in the feeding operation for this interval. Thissituation can be avoided by providing two sets of feeding mechanisms,each with its own balance system, the one set being operated while thesecond set is being reloaded. However, the relatively high cost ofinstalling such additional equipment has generally prevented theadoption of such a procedure. Instead, it has been general practice toreduce to a minimum the time required for reloading the feedingmechanism and rebalancing the scale mechanism,,so that the time requiredto accomplish these operations will be but a small When the advancingpoise has reached the far nism and reset the scale by moving the poiseback along the scale beam to a new position of balance. To the presenttime, it has been general practice to reload the feeding mechanism andreset the poise by hand. These operations, of course, conpercentage ofthe time required to deliver a single charge of raw material to thereaction chamber or other receiving means.

Such a procedure is satisfactory, when the rate at which the rawmaterial is fed to the reaction chamber is relatively small compared tothe time required to deliver an entire load of raw material from theconveyor belt or feeding mechanism to the reaction chamber. However, forcertain types of raw material such as sheets of cellulose used in themanufacture of alkali cellulose, it is economically undesirable eitherto feed the raw material at such a low rate or to construct a feedingmechanism sufficiently large as to make insignificant in an entirefeeding cycle the time required for the reloading and rebalancingoperation. Nevertheless, at the same time, it is essential to thepreparation of a desirable and uniform alkali cellulose, that the errorcaused by these operations either be eliminated or be reduced to anabsolute, minimum. When this alkali cellulose is to be converted intoviscose for the manufacture .of films or filaments of regeneratedcellulose, the

cellulose content of the alkali cellulose (and consequently the rate atwhich the cellulose is delivered to the reaction chamber) must becontrolled to i 0.5%. Such accuracy cannot be economically achieved bythose prior art methods involving the reloading and subsequent handrebalancing of the feeding means.

It is, therefore, an object of this invention to provide means forfeeding at a constant rate and over extended periods of time involvingseveral reloading and rebalancing operations, uniform amounts of a rawmaterial to a reaction chamber or other receiving means.

It is a further oblect of this invention to adapt the "loss of weightprinciple to a continuous operation, whereby that portion of theoperation involving the reloading and rebalancing of the some a certainamount of time during which no feeding mechanism, will not adverselyaffect the continuous nature of the operation, so that it will bepossible to produce a uniform product over extended periods involving aplurality of reloading and rebalancing operations.

These and other objects will more clearly ap pear hereinafter.

The objects of this invention are accomplished. in general by providingin a feeding mechanism mounted on a scale platform and adapted tooperate on the loss of weight principle, means whereby at the end of afeeding cycle feeding action of the mechanism is halted for apredetermined period of time sufficient for the necessary reloading andrebalancing operations, and whereby provision is made for subsequentlydelivering from the feeding mechanism a sufficient amount of rawmaterial to compensate for that amount which normally would have beendelivered during a period equal to this predetermined inactive period oftime.

More particularly, the objects of this invention are accomplished byproviding a feeding mechanism adapted to operate on the loss of weight"principle, and associated therewith apparatus and suitable electricalcontrolling circuim whereby an operator by pressing a single button canbring about the following succession of automatic operations: (1) stopthe further advance oi the poise member of the scale mechanism; (2) setin operation a timing device that will stop the further action of thefeeding mechanism for a predetermined period of time suftlcient for thereloading of the feeding mechanism and for the return of the poisemember to a new position of balance; (3) simultaneously remove from thescale platform on which the feeding mechanism is mounted, a compensatingweight, equal to that weight of raw material that would normally bedelivered by the feeding mechanism during a period equal to thispredetermined period of time; (4) automatically return the poise memberto a new position of balance; 5) automatically return the compensatingweight to the scale platform; and (6) so set the poles member inoperation (advance at a constant rate toward the fulcrum of the scalebeaml that a normal operation of the feeding mechanism again takesPlace. This operation includes the feeding of not only that amount ofmaterial called for by the advance of the poise, but also of that amountof material equivalent to the compensating weight.

Although the apparatus and principles of this invention are applicablefor use in connection with the continuous feeding of almost any type ofraw material wherein a constant and uniform rate of flow of thatmaterial is required over extended periods of time, the invention isparshowing the clutch operating means of the poise drive assembly.

Fig.- 4 is a side view, partly in section showing details of the timingdevice.

Fig. 5 is a side sectional view of the scale beam stabilizer.

Referring particularly to Fig. 1, the apparatus of this inventioncomprises a suitable feeding mechanism mounted on a scale, whichmechanism is preferably of the type disclosed in U. S. Patent No.2,253,140 to Schmitz and comprises a belt conveyor means IIl adapted toconvey a stack 0 of cellulose sheets, and a vertically reciprocatingblade member II adapted to separate individual sheets of cellulose fromthe stack and deliver them to chute I2 of receiving means I3. Theconveyor belt and reciprocating blade mem-- her are activated by motorI4 operating through suitable gearing (not shown) on a shaft extendingthrough a conveyor belt drive roller I5, the operation of the motorbeing controlled by the balanced or unbalanced condition of the scale.This scale comprises a base plate or platform 20 supported on pivotedarms 21 operatively connected by tie rod 22 to the scale beam 23 pivotedon fulcrum 24. The scale beam, provided along its length with a movablepoise 26 is also providedat far end with a contact member 21 whichcooperates with a pivoted lever means 28, to actuate mercury switch MI!in direct response to the successive balanced and unbalanced conditionof the scale. The closing and opening of this switch starts and stopsthe motor H of the feeding mechanism.

Foise member 25 is mounted on, and operativcly connected for movementalong a rotatable threaded member 26. This member is supported on thescale beam by c. main bearing 3% and is coupled to a continuouslyrunning constant speed motor 3| through. a flexible coupling 31., shaft33, and a suitable clutch and transmission assembly 34. Referring nowtoFigs. l2 and 3, the clutch and gear assembly comprises essentially anorm ally engaged clutch 35 to connect the shaft 33 to the motor throughbevel gears lib- 31 and reducer 33; and a normally disengaged multipledisk clutch 33 to connect the shaft 33 to the motor through bevel gearstil-H and reducer. 38, or through bevel gears ll 43 and reducer N. Whenthe connec tion is through low clutch 35, gears 3fi-3l and reducer saucepoise is advanced along the beam and toward the fulcrum M at a slow anduniform rate. When the connection is through clutch disk ticularlyuseful for and will be described in con- 1 nection with the feeding ofcellulosic materials such as sheets of wood pulp or cotton linters toareceiving means for the preparation of alkali cellulose of uniformcomposition.

The preferred embodiment of this invention will now be described withreference to the ac companying drawings wherein:

Fig. 1 is a diagrammatic view showing the or- Banization of the variouselements of the mechanism and the electrical controls therefor.

Fig. 2 is a plan view of a suitable poise drive assembly.

Fig. 2a is an end view of. the friction brake on line 20-h of Fig.2.

Fig. 3 is a side viewpn the line 3-3 of Fig. 2

MI, gears,- ltldl, or sears 'll-43 and reducer 44, the noise is moved ina reverse direction, the poise being moved at high speed through gearslIl--4I and reducer 3B and at low speed through gears 42-43 and reducer44. In a manner to be described hereinafter, the jaw clutch isdisengaged by the action of solenoid Hi6, and the disk clutch is engagedby the action of solenoids I01 and I08 operatlvely connected to theclutches through a suitable arrangement of levers. At one end of shaft33 in the poise drive assembly there is provided an adjustable frictionbrake comprising essentially shoes I21 and Illa supported on block; 126,I2 Ea respectively which in turn are carried on parallel uprights I28and Illa connected by a pressure adjusting screw I 25, (Fig. 2a) Thisproduces a small brakin force which opposes the turning of shaft 33 atall times. When the poise reaches the balance point, at the completionof the resetting cycle, this brake operates to stop the poise screwinstantly, as disc clutch 38 is shifted to neutral position by thesprings shown below oscsoss solenoids ill? and M8 in Fig. 3 This followsthe ale-energizing of solenoid M8 by the opening of mercury switch.till, as hereinafter explained;

At the for end of scale beam 23 suitable means (ill, 65 and E52 Fig. i,are provided to restrict the displacement of the free end of the beamduring the loading of pulp sheets onto conveyor Hi and to control therate of travel of the beam from the displaced to the iii-balanceposition during the resetting oi. the poise.

Stabilizer means 652 comprises ast'abllircr spring -33 fitted in theouter end of a hollow piston 68, which in turn is mounted for reciprocalmovement in cylinder 65 fixeol to the scale cabinet; Compressed. airfed, to cylinder 55 from 3-way solenoid-actuated air valve 98, in themanner herelimiter described, drives piston 63 and hence spring 53 intooperative position while the 001m pression spring 68 fitted aroundpiston 64 and within cylinder 65 tends to urge the piston to itsinoperative position. 7

Springs to and 63 are so designed as to cause the locum to descend otauniform rate during the period when the poise travels to the right athigh speed. At the moment the scale beam extension 29 leaves snring'ilc,the rate or travel or the poise is reduced to low spcerl, whichcontinues until the beam descends to the balance point. The spring onstabilizer 652 causes the scale beam to descend at the same rate as whenthe poise was returning at high speed. Stop screw 551; permits adjustingthe travel of piston 6 130 that when the scale beam reaches the balancepoint, spring G3 touches but exerts no oownworrl force on the scalebeam. The

proper design ancl adjustment of these two springs cause the scale beamto descend very smoothly during the resetting of the poise, unaffectedby the sudden change in rate of its travel as it approaches the balancepoint. As a, result, the beam stops accurately at and does notover-ridethe balance point. Spring 63 is raised. beyond the operating orflooting' range of beam extension 29 at the end of the reloalancingcycle when solenoid tell is ole-energized.

In accordance with this invention, the apparatus also includes 9, timermechanism and a, removable weight it. 'The timer mechanism provides adefinite predetermined period of time for the reloading of the, feedingmechanism and rebalancing of the scoie, while the removable weight makesit possible to compensate for the weight of cellulose that wouldnormally be delivered by the feeding mechanism during the predeterminedpericd of time provided by the time mechanism.

As shown in Fig. 4, the timer mechanism comprises a pair of concentricdisk members and M of different diameter and mounted for rotation inside by side arrangement on shaft 52. This shaft winch completes but onecomplete revolution during each reloading cycle, is connected throughclutch means 53 and. suitable reduction gearing E l to o continuouslyoperating constant speed motor '55. The gearing 54' is so arranged thatthe shaft (curl disks 58, 51} will require, say, 25 seconds (a. periodsufiicient for the reloading of the feeding mechanism and rebalancing orthe scale) for as single revolution. As shown in the figure, the facesof. the disks are provided with v lugs 56, 5'5 oi such proportions thatduring rotation of the disk member, they contact anal open or closeswitches 22 or M3 respectively to make or break certain electricalcircuits to be described later, Lugs 56 one 51 are so locatedmne withresnect to the other and to the switches, that, as the disks rotatetogether, lug 56 first break contact I with switch it? and allows it toclose, and some timclote lug ll contacts switch lit and closes itmomentarily. Clutch means 53 operatively connecting disks and ill withmotor 5% is engaged lay movement of connected levers 58 and 53 opersteelby compressed air fed from 3-way solenoidactuotec air valve in themanner hereinafter clcscrihecl.

The removable weight ill carefully adjusted to equal the weight orcellulose that wcind normally be delivered by the feeding mechanismduring a period equivalent to that provided by the timer mechanism, ismounted on the scale platform olorlgsirie the feeding mechanism. Theweight is lifted from the scale platform by operatively connected leversH, Ti, and i3 actuated by compressed air fed from 3-way air valve inresponse to the energizing oi solenoid lei.

A scale beam locking lever as actuated by solenoid so: is provided tolock scale beam 23 in fixed cally in Fig. 1 wherein. the variouselements are in the condition obtaining during the normal operatiers ofthe feeding mechanism.

Referring to Fig. 1, L1 and In denote the two lea-us or? the main powerline. The circuit comprises essentiolly a. push button switch IM to beclosed by the operator at the start of the reloadino-relaalanciugoperation; a solenoid IN to onerate 3woy air valve 96; solenoid EM tooperate scale beam locking lever to; solenoid 05 to disengage jaw clutch35; solenoids i9? and 108 to engage disk clutch 39 to connect the highand low spcerl reverse poise drives respectively; a commercialmechanical electrical reset relay H0 0! the tyne manufactures hyStruthers Dunn Inc. (Type ABUl.5N) adapted to temporarily hold closedthe circuit initially closed by push button 10%; relay switches ill, H2,H3, and H4; mercur'y switch llil, the opening of which causes the noiseto change from high to low speed reverse during the re-laaluncing cycle;mercury switch m actuated in response to the balanced and unbalancedcondition of the scale beam and effecting intermittent operation ofscale conveyor motor 14; normally-open spring controlled switch I23temporarily helol' closed by lug 51 of timer disk 5|; normally closedspring controlled switch I22 temporarily held open by lug 56 on the faceof timer disk. so; and normally open switch I24.

While the feeding mechanism is in normal operation, glow clutch 35 is inengagement and the poise is ciriven. at a. slow constant rate toward the,iulcrum it. At the same time switches Hi0, i Mi,

Mi, N2 M3, lit, i223, (held open bylug 56) 23 and not are open. The flowof current is then rrom La through the normally closed contact of relayswitch ill, to one connection of the conveyor drive motor it, and fromLl through mercury switch 2% to the other connection of motor is. Aspreviously pointed out, this mercury switch is actuated by the balancedand unbalsnceri conclition of the scale through contact 2] and levermeans 128. when thescale is in a condition oi. science, this switch isopen and no current flows through the circuit. The motor is is stopped.However, as scale beam 28 rises in res and it is ncce operator waitsbalance, as shom' then presses the of this switch on switch H andpeour." to flow to relay switch I l i. Ene ch ill serves to hrcclt theL2 supply to CD3. Juror urlvo motor it, connects the L2 supply tosolenoids lill, Mil, Eilli'l slim, thus completing circuit to thesesolenoids. Energizing solenoid llll opens 3-way sir volvc M which. inturn simultcneonsly causes (ll beam stabilizer 62 to be lowered intooperative position, (2) weight I0 to be lifted from the sonic lJlstiorm,and (3) engagement of clutch to whereby contin i so, lil'lil closing" 20o o coil oi .uously running motor til operates the timer mechanism.Energizing solenoid mi causes looking lever 80 to move into positionunder, cud lock. scale beam 23; energilsing solenoid lilil disciigugeslaw clutch 35 and hence prevents further travel of the poise toward thefulcrum, and at the some time closes switch lM.

Operation of the timer mechanism causes the disks 50, to rotate wherebyprojection 56 of disk 50 is moved out of contact with switch E21 5, thuspermitting the switch to close and form a holding circuit in the L2which circuit duplicates the one formed by the closing of switch I00.Switch I22 remains closed until dish. fill has completed one completerevolution, i. c. imtil the end of the reloading-rcbalancing cycle. Uponcompletion of the first portion of the period provided by the timermechanism (during which time the operator has completed the reloading ofthe feeding mechanism), disc 5! of the time! mechanism has rotatedsuiiiciently for tor its projection 51 to contact and close the normallyopen spring-operated switch H3. The closing of this switch energizes thecoil of relay switch I I2, whereby the Ll line to solenoid it?! isbroken and scale beam 23 is unlocked and the Le supply is extended tothe coils of relay switches H3 and subsequently H4. In the meantime thereloncling of the feeding mechanism has given rise to a large unbalancedcondition. of the settle and since the scale beam is no longer locked,the for end of scale beam 23 is raised and mercury switches I and Illare closed in. the order named. The closing of these switches completesan L1 supply to the coils of relay switches H3 and IN closing switch H3only. closing of switch. H3 brealts the Le supply to switch 5M andenergizes solenoid. Ml whereby disc clutch. 39 is moved to the right(Fig. 3) threaded I'll member 26 of the scale boom is operntivclyconnected with motor El through, gearing Ml, ti, and reducer 38, and thepoise is moved ct high speed away from the fulcrum 24 toward o. position0! balance.

escapee When the poise has moved suiilcieuily far away from fulcrum 24so that the beam is only slightly out of balance (corresponding, forexample, to an overweight amount of about 30 pounds on the feedingmechanism), the outer end of the beam'is lowered to such an extent thatmercury switch in is opened. The opening of this switch ole-energizesrelay H3 whereby solenoid i0! is die-energized and the high speedreverse of the poise member is stopped. The tie-energim'ng of relay H3simultaneously completes the Le. line to the coil of relay switch M l.Closing oi relay switch lit energizes solenoid, ltlll whereby the discclutch so is moved to the lclt (Fig. El) and the threaded member of thesonic boom is opera.-

tively connected with motor 3i through. gearing Mt, ll and reducer M.This causes the '25 to move owuy from the fulcrum c .d to exact positionof balance at a much slowe 'JBBLl. When this position is reached,mercury switch llll is in turn opened, thus breaking the L1 supply torelay switch Bi l whereby disc clutch 39 is re turned to 9. neutralposition, the {gears disengaged and further movement of the :from thefulcrum of the scale prevented.

With the feeding mechanism now loaded and the scale in 9. condition oibalance, the entire apparatus remains stationary (cove il'or the comtinned operation of timer mechanism) until the end of the predeterminedperiod provided by that mechanism. It is, of course, necessary that thereloading and rebelancing operations tnke place sumciently rapidly sothat they will be completed before the end of this period.

At the end of this period lug llli of the disc Ell of the timermechanism again contacts and opens switch ll'l, thus breaking theholding circuit for relay switch ill and causing this switch to "open."

The opening of switch l H breaks the L2 supply to, and thustie-energizes solenoids Nil and Hit. The (lo-energizing of solenoid llllcloses the three-way sir valve 50 to simultaneously (1) dis engageclutch 53 of the time: mechanism from contact with motor 55 and We tionof the discs iii], M; (2) silo.- stcmlizing menus 62 out of contest withthe so thot the beam is free to moi d out .i to the balanced orunbalanced cor ct scole; (3) replace the componsoting' weight if! inposition on the scale.

'lfhc ale-energizing of solo; low clutch 35 to engage We the member 26in the iorw t -sction no move line poise 25 at 0. null fulcrum 24 of thescale. lit N l (closed by the energiuting oi so returned to its normallyo iero opening of this switch. it w l i "the accidental endlg'liillliii, controlling the not? switch ill thus serves w to prevent theengogeil'lcnt o 1 gears til, 41 or M, 43 when i. m cnwclo. Elli T... Lu.engagement.

The of reloy switch. iii the L2 circuit to motor ltl oi truism so thatthis motor o controlled by the closing mud. twitch lid in directresponse i? sliced and balanced conditioi normal operation. This nocontinues until such time scal requires reins entire sequence ofoperations provided by this invention is repeated.-

Although the apparatus has been described above in terms of specificmechanical and electrical elements, it is obvious that manymodifications and changes can be made in the various parts withoutdeparting from the principles of the invention. For example, instead ofemploying the single motor and multiple clutch arrangement of Figs. 2and 3 for the advancing and resetting of the poise along the scale beam,a single clutch means can be used to operatively connect the threadedmember of the poise-advancin means to either of two motors (one foradvancing and the other for resetting) depending on the direction inwhich it is desired to move the poise. If, in such a case, the resetmotor is a variable speed motor, adequate control of the resetting ofthe poise can be obtained by placing resistances in the motor circuit,as the poise approaches a position of balance, whereby the finalposition of the poise can be accurately controlled. Or, the poisedriving mechanism could comprise two separate motors, mounted atopposite ends of the poise driving shaft, one motor serving to drive thepoise in one direction and the other servingto drive it in the reversedirection; the action of the motors would preferably'be controlled in amanner similar to that employed in the preferred embodiment, above, forcontrolling the action of the clutches 35 and. 39. Modifications of theof reactant delivery required in many chemical manufacturing processes.

1. In a controlled material feeding apparatus comprising a beam scale, apoise arranged to move at a predetermined rate on the beam toward thescale construction, timer device, feeding mechf anism, and the otherstructural feature herein disclosed, obvious to the skilled mechanic,are likewise contemplated.

Various modifications can also be made in the electrical circuitemployed for operating the various pieces of apparatus, provided onlythat the proper sequence of operating steps is observed, including theprovision of a definite period of time for accomplishing the reloadingand rebalancing operations, and the provision of a means forsubsequently feeding in a weight of raw material equal to that whichwould normally be fed by the apparatus during a period equal to thispredetermined period of time.

In certain instances, and to prevent an error on the operator's part, itmay be'desired to incorporate into the apparatus of the invention asystem of warning lights or bells to indicate the exact status of theoperation at hand and to warn the operator that the supply of rawmaterial on the feeding mechanism-us becoming low, etc. Such a warningsystem is, of course, contemplated by the invention. 1

The practice of thisinvention makes possible the use of the loss ofweight principle in a continuously operating process wherein greataccuracy in the feeding of raw materials to a receiving means must behad, because the invention substantially eliminates any error in thefeeding of raw material brought about by the time consumed in reloadingthe feeding mechanism 'and resetting the poise of the weighing device.By way of example, the use of the timing device and the automatic resetmechanism of this invention has reduced the error in total weight ofcellulose fed by known types of feeding devices from approximately 5% toless than 0.1%.

A further advantage resides inthe fact that this invention does awaywith the necessity of providing two sets of feeding mechanisms, or ofproviding a feeding mechanism of relatively large, and hence plantspaceconsuming size, in order to achieve the high degree of accuracy inthe rate fulcrum thereof to continuously urge the beam into unbalancedcondition and a material carrier mounted, on the platform of said scaleand provided with means to discharge said material from the carrier,said means being operative to discharge material from the carrier inresponse to the unbalanced condition of the beam whereby to urge thebeam into balanced condition, the improvement which comprises means forsimultaneously stopping the movement of the poise and of the dischargemeans for a predetermined period of time sufficient to permit loading ofthe carrier, means for automatically resetting the poise to a point ofbalance corresponding to the load on the carrier,.and means including anadditional compensating weight added to the carrier immediately afterthe carrier isloaded operatively immediately after said predeterminedperiod of time for discharging from said carrier an added amount ofmaterial to compensate for that amount which normally would have beendischarged during a period equal to said predetermined period of time,said compensating weight being equal in weight to the additional amountof material to be discharged.

2. Controlled material feeding apparatus com prising, in combination, ascale having a load holding platform, a scale beam operativelyassociated therewith, a movable poise on said beam and means forcontinuously advancing said poise at a predetermined rate toward thefulcrum of the beam whereby tounbalance said beam: carrier means mountedon said platform and adapted to support a predetermined load of materialcoupled with discharge means for discharging increments of said load,means for operating said discharge means responsive to the unbalancedcondition of the beam whereby to bring the beam into balanced condition,means for stopping the continuous movement of the poise toward thefulcrum of the beam and for simultaneously stopping the operation of thedischarge meansfor a predetermined period of time suihcient to-reloadthe carrier means, means associated with said stopping means andoperative during said period for returning the poise to apoint ofbalance corresponding to the load on the scale, means for again settingthe poise-moving and material-discharging means in operation and meansincluding an additional compensating weight added to the platformimmediately after the carrier means is loaded for discharging an addedamount of material to compensate for that amount which normally wouldhave been discharged during a period equal to said predeterminedperiodof time, said compensating weight being equal in weight to theadditional amount of material to be discharged.

3. Controlled material feeding apparatus comprising in combination ascale having a load holding platform, a scale beam operativelyassociated therewith, a movable poise on said beam and means forcontinuously moving said poise at a predetermined rate toward thefulcrum of said beam whereby to continuously urge said beam into acondition of unbalance, an advancing material conveyor provided withmaterial discharge means mounted on said platform, said conveyor anddischarge means being operative in response to the unbalanced conditionof the beam whereby to urge said beam into a condition of balance, meansfor simultaneously stopping the advance of the poise and the operationof the conveyor for a predetermined period 0! time sufilcient forreloading said conveyor, means operative during said period forresetting the poise to balance the loaded conveyor, and means includingan additional compensating weight added to the platform immediatelyafter the conveyor is loaded operative immediately after said period tocause said discharge means to discharge an additional amount of materialto compensate tor that amount which normally, would have been dischargedduring a period equal to said predetermined period or time, saidcompensating weight being equal in weight to the additional amount ofmaterial to be discharged.

4. Controlled material feeding apparatus comprising in combination ascale having a load holding platform, a scale beam operativelyassociated therewith, a movable poise on said beam and means forcontinuously moving said poise at a predetermined rate toward thefulcrum of said beam whereby to continuously urge said beam into acondition oi unbalance, an advancing matcrial conveyor provided withmaterial discharge means mounted on said platform, said conveyor anddischarge means being operative in response to the unbalanced conditionof the beam whereby to urge means for simultaneously stopping theadvance of the poise and the operation of the conveyor for apredetermined period of time sufllcient for re loading said conveyor,means operative during said period for resetting the poise to balancethe loaded conveyor means to stabilize the motion of the beam during theresetting operation, and means operative immediately alter saidresetting said beam into a condition of balance,

loading of said conveyor, means ope:

operation to place on said platform a weight of such magnitude that thedischarge means will operate to discharge an additional amount ofmaterial to compensate for that amount which ciated therewith, a poiseon said beam and electrically operated means for continuously advancingsaid poise toward the fulcrum or? the beam at a predetermined ratewhereby to continuously urge said beam into a condition of unbalance, anendless belt material conveyor and associated material discharge means,electrical means for operating said endless belt and discharge meansresponsive to the unbalanced condition of said beam, whereby saiddischarge means is caused to discharge sufficient material to bring saidbeam momentarily into a condition of balance, an electrically controlledtiming mechanism arranged to simultaneously stop the continuous advanceof the poise and operation of the conveyor for a predetermined period oftime sufiloicnt to permit tive during war said period ior resetting saidpoise latter portion of said periolii to balanc conveyor, and to startthe normal is tion or the apparatus at the end oi il "mriod, and meansoperative immediately a or said rcsetting operation to place on saidrti'orm a weight all such magnitude that the liisol'large means willoperate to discharge an additional amount oi? material to compensate forthat amount which normally would have discharged during a period equalto cold promotermined period oi!

